The present invention relates to novel clutch pressure plates and more particularly to a clutch pressure plate fabricated from several sheet steel stampings.
An automotive friction clutch today consists of a clutch cover member secured at its outer periphery to a flywheel mounted on the engine crankshaft, a clutch disc within the cover member and adapted to frictionally engage the flywheel and a pressure plate axially movable to engage one friction surface of the clutch disc and to urge the opposite friction surface against the flywheel. The clutch disc is axially movable but non-rotatably mounted on a driven shaft, and a spring plate normally urging the pressure plate against the clutch disc is located in the cover member to be actuated by a release collar mounted on said driven shaft for axial movement relative thereto to engage the spring plate and release the spring force urging the pressure plate against the clutch disc.
At the present time, clutch pressure plates are conventionally manufactured of cast iron, cast steel or other cast materials that must be formed in a foundry operation. Such a casting is subject to substantial variations in shape as produced by current foundry practice, which results in added time and cost for machining to provide a usable part and when correcting the clutch assembly incorporating this pressure plate for balance. Also, rejects due to foundry errors are a cost problem. The present invention will obviate these problems of foundry casting by providing a fabricated pressure plate.
The present invention relates to a novel clutch pressure plate that is fabricated from sheet or rolled material, such as sheet steel, where the pressure plate comprises two or more pieces formed by stamping operations. Once formed, the individual pieces are assembled and mechanically held together and may be tack-welded for positively retaining the assembly together and to provide further strength. Straightening, if required can be accomplished in a suitable press, and the friction surface, if necessary, could be lightly ground or turned.
Where considerable volume is experienced, the finished individual pieces from the stamping operation would be cleaned and loaded into hoppers or racks to be fed automatically into an assembly machine. The lugs on the friction member would be accurately located on positioning pins while the assembly is rotated and welded where necessary. The lugs for the drive straps could either be formed integral with the friction member or may be formed as separate stampings and assembled and suitably secured to the pressure plate assembly.
The fabricated pressure plate provides a hollow, light weight assembly which will have little variation in shape to affect balance of the plate and will easily meet the high speed burst requirement for clutch pressure plates.
An object of the present invention is the provision of a fabricated clutch pressure plate that is formed from sheet or rolled material in a stamping or progressive stamping operation. The pressure plate is formed of a minimum number of parts to provide a hollow member that is strong but light in weight and low in cost.
Another object of the present invention is the provision of a fabricated clutch pressure plate which is hollow but substantially imperforate for use in a wet clutch assembly.
A further object of the present invention is the provision of a fabricated clutch pressure plate for a dry friction clutch assembly formed as a hollow member with forced air inlet openings on the back side, ventilation openings on the friction facing surface and air outlet openings in the periphery of the plate.
Further objects are to provide a construction of maximum simplicity, efficiency, economy and ease of assembly and operation, and such further objects, advantages and capabilities as will later more fully appear and are inherently possessed thereby.